M. Eng. Gabriela Molinar

Résumé:

Master Thesis done at ITIV under the supervision of Dipl.-Ing. Kai Worms. Title: “Communication and control interface for photonic powered systems”.

PhD student at ITIV from April 2016.

Investigation area:

The strong expansion of wind power combined with the increased international electricity trade has brought the electricity transmission grid to its limits. Since the current state of the line (conductor temperature, sag) as well as the weather conditions in the conductor environment (ambient temperature, solar radiation and wind) are usually not known, network operators are often forced to switch off a large number of wind power generators for safety reasons. The operation of the transmission and distribution networks with such an excessively large margin of safety compared to the actual possible current capacity of the line (also called ampacity) results in significant monetary losses.

In order to enable a greater transport of electricity and thus to avoid the shutdown of wind turbines, a considerable expansion of the existing transmission network appears to be necessary. However, the optimization of the existing overhead lines can be achieved with the use of network reserves via overhead line monitoring systems (FLM). With the use of such systems the ampacity of the line can be measured in real-time. This leads to an ampacity increase from 5% to 20% (in some cases up to 50%).

Really important for the Transmission System Operators is also to have a high quality forecast of the ampacity of the electrical network. The simplest solution to calculate future values of the ampacity is with the use of weather forecasting. If the weather conditions are known at a certain point of time and the maximum conductor temperature is fixed (normally around 80°C), the current load capacity of the line can be calculated. For this reason, a network of weather stations along the overhead line is being researched as part of this project. The data are collected and processed in real time in a central unit, in order to have a self-development of a local weather model in the vicinity of the conductor and to use it for an accurate ampacity forecasting.